The present invention relates to computer animation. More specifically, the present invention relates to enhanced user interfaces for object animation.
Throughout the years, movie makers have often tried to tell stories involving make-believe creatures, far away places, and fantastic things. To do so, they have often relied on animation techniques to bring the make-believe to “life.” Two of the major paths in animation have traditionally included, drawing-based animation techniques and stop motion animation techniques.
Drawing-based animation techniques were refined in the twentieth century, by movie makers such as Walt Disney and used in movies such as “Snow White and the Seven Dwarfs” (1937) and “Fantasia” (1940). This animation technique typically required artists to hand-draw (or paint) animated images onto a transparent media or cels. After painting, each cel would then be captured or recorded onto film as one or more frames in a movie.
Stop motion-based animation techniques typically required the construction of miniature sets, props, and characters. The filmmakers would construct the sets, add props, and position the miniature characters in a pose. After the animator was happy with how everything was arranged, one or more frames of film would be taken of that specific arrangement. Stop motion animation techniques were developed by movie makers such as Willis O'Brien for movies such as “King Kong” (1933). Subsequently, these techniques were refined by animators such as Ray Harryhausen for movies including “Mighty Joe Young” (1948) and Clash Of The Titans (1981).
With the wide-spread availability of computers in the later part of the twentieth century, animators began to rely upon computers to assist in the animation process. This included using computers to facilitate drawing-based animation, for example, by painting images, by generating in-between images (“tweening”), and the like. This also included using computers to augment stop motion animation techniques. For example, physical models could be represented by virtual models in computer memory, and manipulated.
One of the pioneering companies in the computer aided animation (CAA) industry was Pixar, dba Pixar Animation Studios. Over the years, Pixar developed and offered both computing platforms specially designed for CAA, and Academy-Award® winning rendering software known as RenderMan®.
Over the years, Pixar has also developed software products and software environments for internal use allowing users (modelers) to easily define object rigs and allowing users (animators) to easily animate the object rigs. Based upon such real-world experience, the inventors of the present invention have determined that additional features could be provided to such products and environments to facilitate the object definition and animation process.
Traditionally, three-dimensional objects are a collection of three-dimensional objects (components) connected in a manner defined by the modelers. More specifically, these components are connected in a manner specified by an object hierarchy. As an example, FIG. 1A illustrates a representation 100 of a typical object connection hierarchy. In this example, the hips 110 are defined as the root component, with three branches (children), as shown: torso 120, left leg 130, and right leg 140. In turn, torso 120 has a single branch to the chest 150, and chest 150 has three sub-branches, neck 160, left shoulder 170, and right shoulder 180. In turn, each of these three branches includes child nodes. As shown, right shoulder 180 and left shoulder 170 are coupled via chest 150. Previously, the object hierarchy were provided to animators for use in the animation process.
Additionally, various methods were used to allow a user to select a three-dimensional component. One method was via a textual menu or list of the three-dimensional components presented to the user. From the textual list, the user could use a pointing device to point to the name of the component. Another method was via direct selection of a control point associated with the three-dimensional component. For example, the user could graphically select a control point associated with the three-dimensional component on a display with a pointing device. The control point was typically a point on the “skeleton” (e.g. wire-frame, armature) of the three-dimensional component or a point apart from the three-dimensional component.
The inventors have recognized that drawbacks to the above methods include that selection of the control point is often very difficult. One drawback is that because three-dimensional components are represented by individual control points on the display, visually, it is difficult to determine which control points map to which components. Another drawback is that it forces the user to “hunt for pixels” on the display to find the component in interest.
FIG. 1B illustrates the problems above when the three-dimensional object is positioned such that control points and “skeletons” of the three-dimensional components visually overlap on the display. In this example, a portion 105 of a three-dimensional object is shown. In this example, the object represents a side view of a simple person clapping their hands. In FIG. 1B, portion 105 includes an armature 185 that corresponds to the component hierarchy illustrated in FIG. 1A. As can be seen, portions of armature 185 visually overlap on the display. In this example, if the user wants to select the left arm component, but not the right arm component, must first decipher the overlapping objects to determine which control point is the correct one to select. Then the user must carefully click on control point 190 and not on control points 195 or 197. As another example, if the user wants to select a ring finger on the right hand, that task is almost virtually impossible from this view.
In light of the above, the inventors of the present invention have determined that improved user interfaces and methods are desired.